The present invention concerns grip mechanisms for testing tensile strength of materials. More specifically, an improved grip mechanism has been developed which reduces tensile bar failure at the buttonhead of the bar.
One method determining the usefulness of a ceramic material is by testing the ceramic material's tensile strength. In order to test tensile strength, the ceramic material is formed into a tensile bar and placed into a machine that provides a tensile force on the bar. The tensile force is measured at the point the bar ruptures. However, while testing tensile bars on an Instron Grip Assembly a high failure rate occurred at the buttonhead of the tensile bar. When this occurs the tensile strength measurement of the bar is not accurate. The present invention provides a grip mechanism for holding tensile bars that reduces the probability of buttonhead failure.